headphone magnets

There's nothing special about these mini-headphones except that their package uses the word NEODYMIUM in very prominent letters right on the front. It's not every day you see a rare earth being promoted in quite such flashy letters, but they are quite right to do so: It is neodymium-iron-boron magnets that make very small, very light, very good-sounding headphones possible. (To make a speaker sound good you need a strong magnet, and to make it light you need a small magnet. Neodymium-iron-boron magnets are the strongest available for a given weight, which is why they are used in essentially all headphones these days.)
Source: San Jose Airport
Contributor: San Jose Airport
Acquired: 29 May, 2003
Price: $16
Size: 0.2"
Purity: <35%